Laboratory of Food Chemistry and Technology (LFCT), School of Chemistry, Aristotle University of Thessaloniki (AUTh), 54124 Thessaloniki, Greece.
Laboratory of Food Chemistry and Technology (LFCT), School of Chemistry, Aristotle University of Thessaloniki (AUTh), 54124 Thessaloniki, Greece.
Food Chem. 2018 Nov 30;267:410-419. doi: 10.1016/j.foodchem.2017.04.096. Epub 2017 Apr 18.
The stepwise approach takes advantage of simple, versatile, low-cost screening tools that can be applied to several posts of the saffron trade chain to specifically detect adulteration with carminic acid (CA). This natural dye is of insect origin and should not be present in Kosher and Halal foods such as saffron. For gross adulteration levels (>25.0%, w/w) reaction with diphenylamine-sulfuric acid was found adequate to indicate the presence of extraneous matter but not its identity. FT-IR analysis of the dry material combined with chemometrics served to rapidly sort out samples containing >10.0% CA without any sample pretreatment except grinding. Aqueous extracts prepared according to ISO 3632-2 were then examined by tristimulus colorimetry and derivative UV-Vis spectrometry to detect adulteration down to the level of 2.0% (w/w). Determination of CA down to 0.2%, w/w was achieved by RP-HPLC-DAD using aqueous acetonitrile elution solvent (pH=2.8).
该逐步方法利用简单、通用且成本低廉的筛选工具，可以应用于藏红花贸易链的多个环节，专门检测是否掺入胭脂红酸（CA）。这种天然染料来自昆虫，不应出现在犹太洁食和清真食品（如藏红花）中。对于严重掺假水平（>25.0%，w/w），与二苯胺-硫酸的反应足以表明存在外来物质，但无法确定其身份。干燥材料的傅里叶变换红外（FT-IR）分析结合化学计量学可快速分拣出含有>10.0%CA 的样品，除了研磨外无需任何样品预处理。然后，根据 ISO 3632-2 制备的水溶液提取物通过三刺激比色法和导数紫外可见光谱法进行检查，以检测低至 2.0%（w/w）的掺假水平。通过使用水-乙腈洗脱溶剂（pH=2.8）的反相高效液相色谱-二极管阵列检测（RP-HPLC-DAD），可将 CA 的测定下限降低至 0.2%（w/w）。
